Ultrafine nanoporous gold by low-temperature dealloying and kinetics of nanopore formation

A low-temperature dealloying technique was developed to tailor the characteristic length scale of nanoporous gold for advanced functional applications. By systematically investigating the kinetics of nanopore formation during free corrosion, the authors experimentally demonstrated that the dealloying process is controlled by the diffusion of gold atoms at alloy/electrolyte interfaces, which strongly relies on the reaction temperatures. Low dealloying temperatures significantly reduce the interfacial diffusivity of gold atoms and result in an ultrafine nanoporous structure that has been proved to be useful with improved chemical and physical properties. (C) 2007 American Institute of Physics.